Thirteen advanced seismograph systems, called Seismic Research Observatories (SRO), are being installed as part of a program to upgrade the worldwide seismic data network. The SRO system was created by combining a recently developed broad-band borehole seismometer and a software-controlled recording system. The seismometers are being installed at a depth of 100 meters to avoid wind-generated noise in the long-period band. A seismometer output that is flat in acceleration between periods of 1 and 50 sec is used to produce both short- and long-period data that are recorded on analog drum recorders and in digital form on magnetic tape. Very-long-period data, obtained from the seismometer mass position output, can be recorded as well. Digital recording of gain-ranged data provides an amplitude of nearly 120 dB. Preliminary evaluation of the SRO data system indicates that major design objectives have been met. The network of SRO stations will be an important new data resource for seismological investigations, especially for those studies that require computer processing of the data.